[fpc-pascal] Compiler directive: Shared Library

[dibo20 at wp.pl]

Hi,

I'm looking at:
http://www.freepascal.org/docs-html/prog/progch1.html
... and can't find any directive which tell me when I'm compiling a 
shared library. For example:

unit1

{$IFDEF shared_lib}
   Foo: Integer;
{$ELSE}
   Foo: Byte;
{$ENDIF}

....

I always must remember to add own flag in my projects.

Regards